Wednesday, 24 October 2012

I never have been very good at getting up early in the morning. My Mom always used to have to force me out of bed to go to school and I certainly have no desire to get up in the morning in the city, especially as the vast majority of time it is to go to work - not a great incentive! But in the desert it is different, I am often up and out before the sun has risen.

There is a wonderful gentleness to the early hours before the heat of the desert begins to take hold. The softness of air is matched by the softness of colours.

I also love the opportunity to walk around our land and read the signs of who and what has passed our way during the night, it is rather like reading a nature journal written on the land.

A wonderful peaceful way to start the day and get in a positive frame of mind to face whatever the day may bring.

Sunday, 21 October 2012

My husband had been sitting outside eating a granola bar and he had dropped a large nut on the floor. I went out after dark and happened to notice that the nut had gone.

It seems our local cleaning crew was hard at work. This adorable little pocket mouse had found the feast and wasn't about to give it up - look at his cheek pouch! That meal should certainly keep him going for a good while.

Tuesday, 9 October 2012

The last post was diurnal invertebrates so I figured I should feature the nocturnal ones now. In general they tend to be predominantly predators that gather around the exterior lights hoping for an easy meal. We have the regular 'fluffies', beautiful Arizona Blond Tarantulas. This one was a little shy. Tarantulas are nocturnal predators that never venture far from their burrows unless it is mating season. In winter they plug their burrows with soil, rocks, and silk and survive in a relatively inactive state. During this time the animals live off stored fat reserves.

A little later she came out of her burrow and showed off her full magnificence. Tarantulas have an interesting defencive capability in addition to venom. Some of the hairs on the top of the abdomen are specialised for defence. These hairs, are tipped with backward pointing barbs. If a tarantula is threatened in any way, it brushes these hairs into the face, paw or other body part of its attacker. Once these hairs are embedded, they are irritating and very difficult to remove because of the barbs.

A slightly more intimidating predator is the Desert Bark Scorpion, smaller, easier to miss but significantly more venomous. The range of the scorpion is the Sonoran Desert, an adult male can reach just over three inches in length, while a female is slightly smaller, with a maximum length of 2.75 inches. The bark scorpion is particularly well adapted to the desert: layers of fat on its exoskeleton make it resistant to water loss. Nevertheless, bark scorpions hide during the heat of the day, typically under rocks, wood piles, or tree bark. Bark scorpions do not burrow, and are commonly found in homes, requiring only 1/16 of an inch for entry! And it gets better - the bark scorpion is the most venomous scorpion in North America, and its venom can cause severe pain coupled with numbness and tingling in adult humans, typically lasting between 24 to 72 hours. Temporary dysfunction in the area stung is common; e.g. a hand or possibly arm can be immobilised or experience convulsions. It also may cause the loss of breath for a short period of time. Due to the extreme pain induced, many victims describe sensations of electrical jolts after envenomation. Needless to say I took this photo on full zoom :)

Another scary looking predator that is no where near as dangerous, despite it's name is the Tailless Whip Scorpion. Not actually a scorpion, to many it is still the stuff of nightmares and was featured in one of the Harry Potter movies! They possess medium to poor eyesight, however their pedipalps are modified and inward-adapted for grabbing and retaining prey, much like those of a praying mantis. The first pair of legs are also modified and act as sensory organs, while the animal uses the other six legs for walking. The sensory legs (whips) are very thin, have numerous sensory receptors, and can extend several times the length of body. Typically, the animal holds one of these legs out in front of it as it moves, and uses the other to probe the terrain to the side. But fear not, they possess no venomous fangs and they rarely bite if threatened. Don't be tempted to poke them though as they can grab fingers with their pedipalps, resulting in a thorn-like puncture injury.

And to end with, something less fearsome! This is a Mesquite Twig Girdler and it might not be scary to humans but you can be sure that Mesquite Trees are not keen on this little character! The adults emerge in August as the monsoon season is winding down, mate and then
select a mesquite, or sometimes an acacia, as home base. The female then
proceeds to chew a ring around a twig, stopping the flow of sap and eventually
causing that part of the twig to die. She has prepared a nursery for her
offspring, allowing her to lay eggs in the dead part.

Sunday, 7 October 2012

The monsoon has passed but there are still a few invertebrates that remain active around the yard. Arizona does remind me of Africa in many ways, not least of which in the aspect of there seeming to be no such thing as a small bug! Not true of course, there are a myriad of tiny critters but there is also a profusion of large scale characters that to many are rather creepy. This Robber Fly for instance was well over an inch and a half in length. These voracious predators are well adapted to desert climates, where they are known to thermoregulate in
response to temperature variations throughout the day

And the distinctive Horse Lubber is hard to miss. Its big and noisy and when the males take flight they have bright scarlet wings. A relatively large grasshopper species found in the arid Sonoran Desert of the southwestern United States and Northern Mexico. The species is unique in using its black colouration to thermoregulate and the vibrant colouration warns vertebrate predators of its unpalatability and allows the grasshopper to roost conspicuously upon desert shrubs.

I caught this pair of Cactus Longhorn Beetles in a moment of passion before the sun rose one morning! They feed on chollas and prickly pear cacti, and are known to feed on saguaro seedlings. Larvae bore into cactus roots and stems, sometimes killing more susceptible individuals. Adults also feed on the surface of cacti, typically emerging during the summer monsoon season.

And this one was just about to take the plunge into our pool, thankfully I was there to fish it out! Like many flightless beetles, these beetles have limited wing
musculature with a rounded abdomen and thorax. Cactus longhorn beetles
resemble and mimic the behaviour of noxious stink beetles.

We have a small piece of land nestled up against the mountains and this blog is a pictorial record of what occurs there. My only rule, if it doesn't take place on our land - it doesn't get on the blog.